


Inflection Point

by Dequator



Series: M/M Charisk Shit [3]
Category: Undertale (Video Game)
Genre: Anal Sex, Bondage, DMAB Chara, DMAB Frisk, Dicks, Fluff, Gender-Neutral Pronouns, Light Bondage, M/M, Porn with some plot, Smut, absolutely still gay as fuck, cum, they're like 16-18
Language: English
Status: Completed
Published: 2016-08-13
Updated: 2016-08-13
Packaged: 2018-08-08 12:41:46
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 5,742
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/7758256
Author URL: https://archiveofourown.org/users/Dequator/pseuds/Dequator
Summary: <blockquote class="userstuff">
              <p>Chara demands retribution for what happened last time. Frisk is willing to oblige.</p><p>Just smut... Nothing's changed.</p>
            </blockquote>





	Inflection Point

**Author's Note:**

> That took longer than expected. This is easily the dirtiest thing I have ever written.
> 
> For a little bit of not-really-vital context, Chara and Frisk cum at the same time due to ~magic~
> 
> If you are here for the smut (of course you are) then scroll down past all the nonsense to the first horizontal line

It was warm outside, the homely, magical warmth of the Dreemurr household slowly pouring out and pooling up on the backyard deck heralding a cathartic stargazing session between Frisk and Chara. The interloping heat, coincidentally, seemed to parallel their varied topics of discussion.

“Anyway, it’s getting _boring_ out here.” The sound of rustling fabric beside Frisk indicated that Chara was getting up.

“Wait!” They badgered, whipping their head around for confirmation that Chara was, indeed, about to leave. “Stay here, just for a little while.”

“Why?”

Frisk quickly thought of a reason. Really, they were just too lazy to get up. And, of course, they wanted Chara to stay.

“Uhh… I wanted you to tell me what you know about stars,” they blurted out haphazardly, pointing upwards at the clear night sky. “Please?” Frisk pouted at them adorably.

…Chara really needed to work on saying no to that face.

“Fine.” Chara sat back down. “I don’t know any of the constellations because I’ve been dead for over a decade and don’t remember them,” they said morbidly.

“That’s okay.” Frisk gave them a reassuring pat on the shoulder.

“But I know a lot about them because I’m a massive dork.”

Frisk didn’t disagree. “I’m all ears.”

Chara drew in a deep breath. “Stars are like, big nuclear reactors,” they began. “In the core of a star, the intense gravitational energy and high temperature causes hydrogen atoms to fuse together in a process called nucleosynthesis.”

They pretended that Frisk wasn’t staring at them adoringly with wide eyes as they drew in another breath to continue. They also worked under the assumption that Frisk understood half of what they just said – it was unlikely, but nevertheless, they seemed interested.

“When hydrogen atoms in a star fuse together, they form a helium and release a shit-ton of energy which we see here on Earth as heat and light.”

Frisk shuffled closer, eager to savour the rare, endearing occurrence of Chara nerding out over something.

Chara continued their seamless explanation. “Larger stars, maybe like that really bright one near the moon over there,” they said, pointing upwards and making sure that Frisk was looking. “Have a lot more energy to work with. When they run out of hydrogen to fuse into helium, they can keep fusing atoms together to create heavier and heavier elements. The Sun, for example, when it runs out of hydrogen it will become a red giant and begin fusing helium atoms into heavier elements like oxygen and carbon.”

The devoted student tucked their knees into their chest, listening faithfully.

“Really, _really_ massive stars can fuse together even heavier elements like iron and copper. It’s theorized that the atoms that make up everything around us – me, you, and the ground we’re sitting on,” they informed Frisk, waving their hands around. “Were formed in the cores of massive stars by nuclear fusion before they died and exploded in supernovae, releasing huge amounts of matter into space that later reformed as planets like Earth, or facilitated the formation of new stars like the Sun. That means you and I were made in stars.”

“Wow, Chara.” Frisk was rapt, with adoration rather than understanding of newfound knowledge. “I always knew you were a star.”

Chara nudged Frisk’s side with a gentle elbow. “You too,” they mumbled, stretching their legs out and then leaning back on their palms, pacing their fingers over the gaps between the wooden panels.

“You should do that more often about other topics.”

“I don’t know if I can. I feel like a nerd,” they huffed.

“You _are_ a nerd,” chuckled Frisk, leaning aggressively into their shoulder. “Might as well go all-out.”

“Fine. Maybe some other time.”

“Hmm… Hey, how much energy does the Sun release?”

They raised an eyebrow at the oddly-specific question. “…You actually care about that?”

“Yeah. You make things interesting.”

Chara chuckled. “Well, when atoms fuse together, the resultant energy can be calculated using the famous E equals MC squared formula that no one really understands. The energy released is the difference in mass between the reactants and the products multiplied by the speed of light squared, which is a number sixteen digits long. In joules, of course.”

Frisk raised an eyebrow in confusion. “Care to explain that in a way someone who isn’t a nerd can understand?”

“The sun is a relatively small star, but there are millions of fusion reactions happening within it every second. Thus it has enough energy to burn brighter than a billion trillion lightbulbs and hotter than every volcano on earth combined at a temperature of fifteen million degrees, for its entire lifetime of ten billion years.”

Frisk sneered. “So… in other words, the Sun is about one millionth as hot as you?” Their attempt to get Chara to stay with them to resulting in some cringe worthy but lovable flirting was inevitable, they thought.

 “You’re sickening.” Chara objected, face reddening.

“It’s what I do, and you love it.”

“Just sickening.” Chara forcefully poked Frisk’s cheek, sending them scuffling away.

“That isn’t what you said the other night~” they cooed. Frisk decided to get up despite their endeavour to remain seated, and Chara quickly followed suit.

“You made it very difficult for me to say anything at all.” Chara shoved the other human through the doorway and into the permeating warmth of the house, quietly closing the door behind them as they entered.

“Poor Chara,” they teased, quickly scuttling off down the hallway with Chara close behind them. “You know, that whole sixty-nine thing is kinda funny,” they said rather audibly over their shoulder. Hopefully, no one was awake to hear that.

Chara glanced at them quizzically. “Funny? Why?”

 “Because we just suddenly did it.” Frisk shuffled about on the soft, fuzzy carpet inside.

“It was _your_ idea,” intoned Chara.

“I _know_ , Chara. I’m glad I had that idea, too,” they admitted. “But think about it for a second. We went from… this, to that, really quickly, don’t you think?”

Chara smirked at the other human. “By ‘this’ and ‘that’, you mean ‘meekly talking about jerking off’ and ‘full-on throat-ravaging sixty-nine’ respectively, right?”

“Yeah.” Unperturbed by the rather… vivid reiteration, Frisk put on a mischievous grin. “I’m surprised it took us so long.”

“It’s your fault.”

“I guess.”

“You aren’t regretting it, are you?”

Frisk furrowed their brow. “What? No. Why?”

 “You sounded like, repentant.” they reasoned. “Like you’d committed a sin of the highest order.”

 “I’m far from repentant about it.” Frisk reassured.

 “Obviously.” Before Frisk could hurry away, Chara called out to them. “You know, Frisk…”

“Yup?”

“I still need to get you back for that throat-ravaging incident.”

“Mhmm. Indeed you do.” Frisk stopped abruptly in front of them, almost resulting in a collision. “Actually, wanna eat something first?”

Chara nodded without hesitation to the latter part of the proposal. “Wait, you’re serious? Just like that?”

“…Yes? We have plenty of food…”

“No, no, the ‘me getting you back’ part.”

“Oh. Well, yeah.” Frisk tugged on Chara’s sweater, dragging them to the kitchen. “I know I was all funny to talk about it the first time but since we’re probably gonna be doing this for a long while we should just be open and cool about it.”

“I didn’t mean it that way.”

Frisk coddled Chara onto one of the dining table chairs, forcing them into a seated position. “In what way did you mean it, then?”

“I meant-“

They gently put a finger up to Chara’s lips. “Hold on. Let me get some food first.” Frisk retreated around the corner to the fridge, leaving the other human to drum their fingers on the smooth wooden table top.

Like their previous homes, the latest Dreemurr household was nothing spectacular; you wouldn’t expect royalty and one of the biggest political figures of the present day  – the frisky ambassador themselves, Frisk – to be living in a rather small, cosy house like this one. Most of the house was adorned with noble purple wallpaper, and the majority of the furniture was constructed intricately from vintage timber. There was very little clutter; aside from chairs in the appropriate rooms, one would find only generously-populated bookshelves and small tables with flowerpots and vases atop them. With everyone but Frisk and Chara fast asleep, it was remarkably serene and quiet, too.

Perhaps such a cosy, bare-necessities lifestyle was strictly a monster thing, as Frisk and Chara’s room was an utter wreck with clothes, gadgets, books, and food scattered around aimlessly. Had there not been a bin in their room, the large stockpile of tissues inevitably produced by the teenage pair would probably find itself evenly distributed amongst all the untidiness as well.

Frisk returned with two sizable portions of pie. As always.

“No chocolate,” lamented Frisk with mocking sorrow.

“Tragic.” Chara eyed the plate as Frisk set it down in front of them while they sat across the table, already taking a large bite.

“Anyway,” they began with a mouthful of un-chewed food. “What were you saying?”

“Oh. I meant like, since you have no idea what me ‘getting you back’ involves, I was just surprised that you’d be cool to go ahead with it.” Chara bit into their pie. There was something weird about eating monster food. It didn’t seem to fill you up as you ate, it kind of just… ‘reset’ all the negative effects of _not_ eating. On an unrelated note, it also meant significantly fewer trips to the bathroom were needed since it was absorbed into your soul or something like that.

“Last time was pretty messed up and I enjoyed that a lot, so I’m okay with whatever you have in mind.” Frisk rapidly blinked a few times. “…And I _really_ need to blow off some steam,” they added.

Chara chuckled, almost spitting out a few pie crumbs. “I’m so glad you’re so open and keen about this. I thought it would take a lot of convincing just to get you to even think about doing that kind of thing with me.”

Frisk giggled, grinning at Chara with a mouthful of food.

“I’ll take whatever I can get from you, now,” they blurted before pulling out their phone to check the progress on all their silly games.

“Put that away,” commanded Chara. “It’s _rude._ ”

“Sorry. I’m checking something.” Frisk took their time collecting coins and experience from all the little buttons on their phone screen.

Chara propped up their head with their palm, elbow against the table in an extremely dissatisfied fashion. “I’m gonna delete all those games from your phone one day.”

“You wouldn’t dare.”

“I would.”

Frisk smirked before swiped over to the next game. In this one, they had to defend their kingdom from attacks against hostile armies. It was Chara’s least favourite of all of them, because every time Frisk’s kingdom was attacked they’d spend hours glued to their phone repairing everything.

“I’ll delete all your porn and photos of me,” they chuckled.

“What photos of you?”

“You have some rather… ‘candid’ images of me on your phone, I’m pretty sure.” Frisk tapped rapidly on their phone screen to speed up the construction of a building.

“You can delete them if you want,” scoffed Chara, slowly chewing another mouthful of butterscotch and cinnamon pastry. “I’ll just use your UnderNet profile instead.”

Frisk raised an eyebrow. “Seriously? There’s like, two photos of me on there.”

“I can make it work.”

“One of them is from when I was like ten years old in the Underground,” they grimaced.

“The other one.” Chara resisted pulling out their phone and refreshing their memory. “It’s a nice photo.”

“I’m honoured that you’d go to such lengths just to jerk off over a photo of me,” Frisk giggled, eyes not having left their phone screen since they got it out.

“Don’t flatter yourself.” Chara flicked a pie crumb into Frisk’s hair. They didn’t notice at all.

Finally, having harvested every last digit of experience, gold, gems, and other forms of currency from the trove of cheap knock-off mobile games they had, they put their phone face-down on the table. Chara still looked slightly irritated, so they slid it across the table top as an act of appeasement, allowing them to do whatever with it. Hopefully _not_ delete all of their games.

“So what do you have in mind for this ‘revenge’, Chara? “ They asked, somewhat fearful and somewhat hopeful.

Honestly, they’d thought about what they’d do to Frisk if they’d had their way with them for a long time. Even before they had any reason to exact ‘vengeance’ upon Frisk.

“…It’s a surprise?”

“What a tease,” they scoffed, swallowing the last of their pie.

“You remember what I said last time, right?”

Frisk nodded slowly. ‘On top’ and ‘rough’ if they recalled correctly.

“Mayyybee... I think I should be more specific.”

“Mmm?” Frisk leaned forward, staring into Chara’s adorable crimson eyes with a silly smirk on their face.

“I wasn’t gonna tell you until it was too late for you to object, but…” Chara pushed their plate into the middle of the table, finishing their portion of pie.

“…But?”

Chara looked down at their fingers tapping away against the surface of the table, licking their lips slowly.

“Boy, you’re gonna love this.”

Frisk opened their mouth, but was shortly interrupted. “Am I-“

“…I’m gonna tie you up and fuck you until you _scream_.”

 _Holy shit,_ Frisk thought to themselves. Chara heard.

They fidgeted, face burning bright red and excitement immediately welling up from within. They couldn’t honestly say they weren’t expecting that and that they had never thought about it, but hearing it come out of Chara’s mouth like that…

“…Nice.”

“You’d like that, wouldn’t you?” Chara remarked.

Frisk could only muster a nod.

* * *

 

 

Chara stood above Frisk who was seated on the edge of the bed beside their discarded pile of clothing, holding a towel, as well as some other things, the sheer sight of which made Frisk tremble and shiver with arousal as they eyed the other human up and down lustfully in the dim light.

Chara’s body was similar to Frisk’s, although less effeminate.  While Frisk had a body that would make a significant percentage of the male population question their sexuality, Chara’s body was more straightforward. They were rather thin, somewhat fit and toned, slightly broad-shouldered, and had a fair, light complexion that contrasted Frisk’s even sun tan.

If Frisk leaned forward and down just a little, Chara’s already rock-hard dick would be perfectly in line with their throat.

Looking at it now, they realized that it’s actually kind of big…

“Towel?” They asked timidly, shaking those thoughts out of their head for now.

“Yes. You’re going to cum at least three bucket loads onto this afterward,” said Chara, straight-faced. They tossed the towel on the bed behind Frisk, their prediction giving them a clear idea of what position Chara was going to put them in.

“And… Those?” Frisk nodded towards some rope and a clear bottle in their other hand.

“Can’t you tell?” Chara chuckled. “Or does me saying it get you off?”

“Mmm…” They wiggled their bare hips on the sheets.

Chara dangled the thread of rope in front of Frisk’s wide-eyed, lustful face. “This is to make sure you don’t do anything I don’t want you to do,” they whispered.

“…Uh-huh.” They shuddered with desire.

Chara lifted up the clear bottle. Frisk was unable to read the label. “And this is to make you nice and slippery so I can get deep inside of you,” Chara cooed.

They cupped Frisk’s cheek, stroking it gently, then ran their hand slowly down the side of Frisk’s neck.

Frisk leaned into the touch, eager for affection.

Chara’s hand trailed slowly down Frisk’s chest, sending them shivering and gasping where they sat as the smooth fingertips made their way over their abdomen, and they contemplated what was to come.

“…That way, I can make you scream like I said I would.”

Frisk squealed with half-embarrassment and half-excitement, now sitting right on the edge of the bed, threatening to fall off. Where, should they actually fall off somehow, they’d certainly land on Chara’s horribly tempting dick…

Disappointingly, Chara withdrew their hand from Frisk’s luscious body before it got anywhere… pleasurable, smirking teasingly at them from their elevated standing position.

Desperate for some kind of relief, they began slowly stroking themselves while Chara made sure the towel was spread out over the sheets, watching them intently. They squeaked quietly as they found it to be especially enjoyable, closing their fingers around their rock-hard, throbbing shaft.

Behind them, Chara started chuckling. They wondered why, until they felt Chara’s own hand close around their wrist, torturously pulling it away from their aching member.

“C-Chara…” Frisk mumbled. “Please, I-“

“Shhh.” Chara leaned in close and pressed a gentle kiss to Frisk’s lips, before pulling away and putting their hands on their shoulders, running them down their sides. “Can’t wait, can you?”

Frisk slowly shook their head, staring right into Chara’s lustful eyes.

“Me neither.” The fair-skinned human climbed onto the bed, crawling behind Frisk and crossing their arms over their defined, tanned back so that their forearms were lined up in parallel. “Hold your arms there for me, okay?”

Frisk nodded obediently, shuddering as they recognized what Chara was doing.

They drew in a sharp breath as the rope Chara was holding wrapped tighter and tighter around their crossed wrists, the harsh pressure of the thread against their bare skin contributing significantly to their already potent arousal.

Experimenting a little, Frisk tried to move their arms out from behind their back, yet they wouldn’t move an inch against the restraints.

“Is it too tight?” Chara leaned over Frisk’s back, their hot breath wafting down their sweaty neck with each long, impatient exhalation.

“N-No…” They tried again to separate their hands, yet to no avail. They thought about the predicament they were in – Chara had literally just tied them up and was about to fuck them into oblivion – and almost let out an abrupt, random moan.

“Good.” Chara picked up the clear bottle from off of the floor and held it valiantly in one of their hands, the other one placed on Frisk’s shoulder to guide them into position. “Lie on your back over there,” they commanded.

Frisk did as they were told, shuffling about with Chara’s assistance so they were lying down facing the ceiling – a familiar position – with their rock-solid cock pointing straight upwards and their head comfortably rested upon the pillow, wrists still bound tightly behind their back.

They trembled with anticipation as they heard the pop of the bottle cap being flipped open, and the squirt of its contents onto Chara’s palm.

“I’m sorry if it’s uncomfortable to lie on your back,” they whispered. “I’ll fix that soon.”

“W-why like… this?” Frisk muttered.

“I want to see your face when I put it in for the first time.”

Frisk swallowed, face ablaze with embarrassment.

Chara gave their thigh a teasing slap, gesturing for them to spread their legs. Frisk did so devotedly, pulling their knees up to their chest and looking downward between them to watch Chara.

They were staring straight into Frisk’s eyes, grinning lewdly, before they teasingly dragged a wet lick up the underside of Frisk’s throbbing member, causing them to buck their hips upward and let out a whimper.

“Alright, Frisky. Let me know if you want me to stop.”

Chara’s head bobbed down beneath Frisk’s lewd horizon, and all they could do was throw their head back on the pillow and swim in the sensations that were about to follow.

Chara pressed one of their fingers against Frisk’s entrance, lathering it in a generous amount of lube before they slowly pushed their finger inside, it gliding in almost effortlessly and eliciting a squeak from the bound human.

They gently wriggled the finger about inside them, rewarding them with aroused moans and excited jerks and twitches as they experimentally moved their finger in and out before adding a second finger, evoking yet another squeak from Frisk.

The sensation was blissful; it felt like they were allowing themselves to be invaded and conquered by intense pleasure, the feeling of Chara’s fingers working deeper inside of them and spreading them apart further and further so alien and unfamiliar that they desperately longed for more, moaning and shivering atop the bedsheets as Chara continued to fingerfuck Frisk’s wet, slippery ass, sending them arching their back and pulling against the bindings on their wrists.

Chara wasn’t able to share the alien sensation of being filled, only the pleasure that it resulted in – and that was enough to make them speed things up as they pushed in yet another finger, spreading Frisk wide open and causing them to outright cry in intense pleasure and ecstasy.

“C-Chara… I want…”

“Mmm?”

Slowly, Chara slid their fingers further and further out of Frisk’s loosened entrance, before they withdrew completely and left it slightly open before it slowly closed properly, decent amounts of lube still dripping out.

“Please, I…”

“You talk too much.” Chara climbed on top of Frisk and bit into their neck gently, dragging their tongue up and down the smooth skin. “I don’t want to hear anything from you that isn’t a moan, a scream, or my name, alright?”

Frisk nodded slowly, whimpering from the other human’s kisses.

“Try to relax.”

Chara pulled away, the tied human’s legs still spread out and in the air for them, keenly inviting them to enter Frisk’s ass and bathe them in rough, ecstatic pleasure. Biting their lip and holding on tightly to one of the bound human’s thighs for balance, they lined up their pulsating, pre-dripping cock perfectly with Frisk’s wet, loosened entrance, pressing the tip teasingly against the sensitive flesh.

Slowly, they prodded the tip of their slick cock into Frisk’s hole, biting harder on their lower lip as it opened to accept and the tight, fleshy warmth began to embrace their hot member while Frisk shook beneath them in eagerness.

Frisk’s breathing sped up and they gaped wide-eyed at Chara, the girth of their invading dick being much larger than the three fingers they’d had inside them before.

Suddenly, Frisk’s entrance gave in to the slick, pulsing member, allowing them to glide in effortlessly and hilt their shaft into Frisk’s quivering ass, drawing out a long, deep moan from Chara. The effect was much more potent for Frisk, sending them arching their back and kicking out their legs around Chara’s waist while they let out a loud, lustful moan of raw bliss into the heady, dank air of the bedroom, eyes rolling back and wrists painfully struggling against the tightened rope while their breathing rapidly sped up and the constant rising and falling of their chest became much more frequent.

They’d remember that reaction forever. Regaining their composure, Chara gripped onto both of Frisk’s raised thighs and triumphantly watched Frisk squirm and lose themselves to the sensation as they slowly slid their hard cock out of them, lowering their hips a little in order to hopefully angle themselves better for the next thrust. They used more force this time, driving their cock deeply into Frisk’s insides.

The effect of their angled thrust was immediate as their dick pushed harshly right into Frisk’s prostate, the tied-up human outright shaking and whimpering while letting out a worringly loud cry of pure bliss and tightening the grip of their thighs around Chara’s waist.

“Chara!”

Frisk’s eyes rolled all the way back and their tongue lolled out freely, face turning bright red and arms becoming sore from pulling roughly against the rope that secured their wrists in place. A potent jet of pre lurched out of Frisk’s cock purely from the single thrust, splattering all over their silky chest. Frisk wiggled and ground their hips up against Chara and threw their head to the side, completely overwhelmed with both the pleasure of Chara’s fiercely hard cock reaching deeply into their ass and grinding up against their prostate, and the sensations of their own inner walls clenching around their throbbing length that they shared through the intimate bond between their souls.

Chara’s eyes opened wide as they launched a spurt of precum into Frisk’s ass themselves, groaning at full volume and digging their fingers into Frisk’s thighs as their whole body trembled from the feeling of Frisk’s hot, wet insides clamping down on their dick and the aftershock of the effects their deep penetration had on Frisk’s rapidly-failing composure.

“H-Holy… fuck…” Chara panted, reluctantly dragging their cock out of Frisk’s tight ass, as much as they wanted to just continue pounding into them. “Nghh…”

Frisk blinked rapidly, still hyperventilating and sweating from the single thrust of Chara against their prostate. The bound human seemed disappointed and worried that Chara had stopped.

“Let me roll you over.”

Frisk obeyed, allowing Chara to gently roll their sweaty, rapidly-breathing body over and onto their stomach, rewarding Chara with a rather arousing view of the human. They went limp, contributing very little to Chara’s task, instead allowing them to simply have their way with their hot, slick body. This _was_ revenge, after all.

They felt their hips being lifted up and tucked their knees inward in response, now lying stomach-down, face buried in the pillow and turned to the side to catch Chara’s flushed body in their peripheral vision, and their ass being outright presented in the air to Chara with their hands still tightly sealed together behind their back, preventing them from doing anything but let themselves get fucked.

“If you can’t hold it in, Frisk…” Chara whispered. “Scream into the pillow, okay?” They were confident in their ability to stay quiet, but knew being on the receiving end must be a whole different thing.

Before they could respond, they felt Chara’s familiar length easily slide back in to their tight ass with a loud squelch, biting down hard on their lip and clenching their eyes shut hard from the intense pleasure, unable to keep themselves from kicking their legs a little and arching their back.

Chara grunted loudly, giving Frisk’s round, silky asscheeks a forceful, lustful squeeze as they reeled their slick member out of Frisk, deriving great satisfaction simply from watching Frisk squirm and whimper that yet paled in comparison to the feeling of the hot, slick walls pressed tightly around their dick from all angles. Again, they angled their hips downward slightly so that they would collide into Frisk’s sweet spot with each thrust.

Frisk whimpered from Chara’s groping before they felt their throbbing member grind up against their prostate once more, forcing out a long moan and a full-body jerk that resonated so strongly throughout Frisk’s trembling body that Chara was able to feel it in its full glory, eliciting a long moan that forced them to bite their tongue. The fair-skinned human watched the fine muscles along Frisk’s back tense and ripple as they reflexively fought against the bindings on their wrists, driving them to use more vigor in their thrusts.

Chara worked into a steady rhythm, pumping in and out of Frisk without hesitation or clumsiness, hilting deep into them and letting out lustful grunts and the occasional loud, pleasured moan as they sank in and reeled out of their tight, wet ass.

The tanned human let their eyes roll back and their tongue dangle out, drooling carelessly all over the pillow as they submitted fully to Chara’s determined pounding, their mind swimming in pleasure. Every time their dick pushed in deeply enough to grind up against their prostate their ears would ring for a second or two and they would start seeing stars before a squirt of pre would erupt onto the towel beneath them, a drawn-out moan or high-pitched squeal inevitably escaping their parted lips.

Chara sped up, leaning over Frisk so they could use more force to thrust into their ass, the sounds of Chara’s grunts and moans, the sound of their sweaty hips slapping against Frisk’s ass, and the sound of Frisk’s squeaks and cries reverberating off of the walls. Frisk’s cries became louder and more frequent, forcing them to bury their face into the pillow as they gave in to Chara’s intense fucking, their depraved mind now drowning in pleasure.

Their cries and the pleasure they were feeling begged Chara to speed up, running their hands down Frisk’s thighs and over their back as they slammed their hips into Frisk’s hole over and over again. They felt the familiar pressure building up somewhere, somewhere they couldn’t feel, indicating that Frisk was about to cum, their suspicion supported by their increasingly loud moans and blissful twitches of ecstasy. Chara contemplated drawing this out, slowing down or stopping abruptly, but the pleasure was simply too much yet they _still_ wanted more.

Frisk’s breathing became irregular as the familiar sensation of release began to spread throughout their body, their muscles tensing and their dick flexing instinctively as they sent wads of precum rocketing across the towel beneath them in the moments leading up to what was sure to be a brain-frying orgasm.

Chara’s final few thrusts were deliberately aimed directly at Frisk’s sensitive spot, pounding as hard as they could in order to grind against Frisk’s prostate and let out the intense pleasure between the both of them like a match being struck on the head. The rapid thrusts caused Frisk to clench their eyes shut and squeeze their hands as tightly as they could, arching their back and outright screaming in bliss as they began to cum while their eyes watered and they bit harshly into the dampened fabric of the pillow.

The pillow failed to stifle Frisk’s noises; cries, moans, and squeals easily audible over the sound of Chara’s hips slapping against theirs as well as the fair-skinned human’s own moans of ecstasy.

Frisk’s hot cum outright sprayed all over the towel, the liquid sounds it made as it vigorously splattered beneath them effortlessly able to be heard beneath all the other sounds of arousal. Their whole body shook and trembled, their breathing hitched and sped up unimaginably quick, and they half-screamed, half-moaned lewdly deep into the pillow, legs kicking and their untouched dick constantly pulsing with each jet of cum they launched downward.

Forced to oblige, Chara came with them, hilting their dick as hard as they could inside Frisk and groaning loudly into the air. Their thick, white seed poured into Frisk, flowing freely into their insides and splashing about between their fleshy, abused walls, the sensation of Chara’s hot, sticky fluids gushing into them filling them with perverse, depraved ecstasy as they felt their fingernails dig into their supple ass cheeks. The aftershocks of Frisk’s intense orgasm almost caused Chara’s legs to give out beneath them, bracing some their own weight on the other human’s back while the two humans experienced intense, synchronized orgasms.

It all became far too much for Frisk to handle, an assault of sensations from all directions, from the inside and from the outside. As their orgasm tapered off, their breathing slowed rapidly alongside their heartbeat, and they felt their muscles weaken and give out from underneath them as their consciousness faded out into a starry void.

Chara slid their cock out of Frisk’s abused ass and released their death grip on Frisk’s luscious thighs, and the unconscious human collapsed into a puddle of their own cum.

 

* * *

 

Frisk woke up atop their unsullied bed, carefully wrapped up in blankets with someone close beside them. Probably Chara. They blinked their eyes a few times, rubbing out the crusty feeling that naturally came with having had them closed for what seemed like weeks.

They tried to sit up, but yelped with discomfiture as a dull ache permeating throughout their ass reminded them of what caused them to be in this state, and collapsed back down onto the pillow, staring straight ahead.

“Oh, you’re awake,” Chara whispered. “How are you feeling?”

“…Good?” Frisk said, puzzled. “How long was I out?”

“Only a few hours. Don’t worry about it.”

Frisk giggled. “How nice of you to clean me up and stuff.”

Chara threw their phone recklessly onto the floor. The same kind of recklessness that they wished Frisk would have when it came to parting with their own mobile device.

“I wasn’t gonna leave you tied up in a twelve-litre puddle of semen,” they reaffirmed. “And yes, you did cum that much. I literally had to slip outside and dump the towel in the bin beside the road. Easily the worst part about us having magical in-sync orgasms.”

They couldn’t help but feel somewhat triumphant knowing that. “I, uhh… Thanks, Chara.” Frisk rolled over and pulled the other human in for a warm hug.

“It’s funny,” Chara started, wrapping their arms gently around Frisk’s waist. “I probably came the same amount into you. I wonder what’s gonna happen to it.”

“I…” That’s an… interesting thought. “I’ll probably digest it?” Frisk thought back to how it felt when Chara came inside of them, that invasive, hot, spreading slickness…

“Sounds better than having to almost drown in it,” they jested. “You know, you sounded like you had a real good time last night.”

“Obviously,” they said, cheeks turning red. “You fucked me until I came so hard that it knocked me out.”

“It’s an honor,” they said jubilantly.

“That was one unforgettable first time, though.” Frisk whispered.

“Mmm.”

Frisk only noticed now that neither of them were wearing any clothes. Rather than feeling uncomfortable, it felt… nice. Chara’s skin was soft and warm like theirs, and feeling it rub against one another’s without anything in the way was so relaxing.

“I hope no one heard us, Frisk. You’re pretty, err, ‘vocal’.”

“I wouldn’t worry about it. They’re all pretty heavy sleepers.”

Frisk nuzzled into Chara’s bare chest, brushing their cheek up and down against the soft skin. Chara returned the affection, feeling over the fine muscles of Frisk’s back.

“You should let me show you what it’s like next time,” Frisk suggested.

“You want to fuck me?”

“Yup. I need to exact vengeance on you for that.”

“Honestly, I’m pretty curious after seeing you scream and moan like that,” teased Chara, poking Frisk’s face. “Sure.”

“And so begins the endless cycle of getting ‘revenge’ one on another as an excuse to have crazy sex,” they giggled.

Frisk leaned forward and kissed Chara on the lips.

 

 

 

**Author's Note:**

> I kinda need to come back down to earth after writing this. Still... I don't regret anything.


End file.
